|Year : 2017 | Volume
| Issue : 3 | Page : 203-204
Unrare but unfamiliar preauricular pilomatricoma mimicking parotid tumor
Anna Park, Jeong Hwan Choi
Department of Otorhinolaryngology Head and Neck Surgery, College of Medicine, Sanggye Paik Hospital, Inje University, Seoul 139-707, Republic of Korea
|Date of Web Publication||31-Aug-2017|
Jeong Hwan Choi
Department of Otorhinolaryngology Head and Neck Surgery, Sanggye Paik Hospital, College of Medicine, Inje University, 761-1 Sanggye-7-dong Nowon-gu, Seoul 139-707
Republic of Korea
Source of Support: None, Conflict of Interest: None
Pilomatricoma is a benign skin tumor arising from the outer root sheath cell of the hair follicle that usually present in the head and neck region. Pilomatricoma usually presents as an asymptomatic, solitary, firm or hard, freely mobile, dermal or subcutaneous nodule, and exhibits no fixation to neighboring tissues and has a cartilage-like hardness. The characteristic image findings are reported as well-defined subcutaneous masses with or without visible calcification. Despite these general clinical characteristics, the preoperative diagnosis-based solely on the clinical examination is often difficult because of various manifestations frequently presented by the tumor.
Keywords: Parotid tumor, pilomatricoma, tumor
|How to cite this article:|
Park A, Choi JH. Unrare but unfamiliar preauricular pilomatricoma mimicking parotid tumor. Indian J Otol 2017;23:203-4
| Introduction|| |
Pilomatricoma, also known as calcifying epithelioma of Malherbe, is slow-growing skin neoplasm of follicular cell origin that usually present in the head and neck region with bimodal distribution in children and under the age of 20 years adult. It usually presents as an asymptomatic, solitary, firm or hard, freely mobile, dermal or subcutaneous nodule, and exhibits no fixation to neighboring tissues and has a cartilage-like hardness.
Despite these general clinical characteristics, the preoperative diagnosis-based solely on the clinical examination is often difficult because of various manifestations frequently presented by the tumor. Clinically, the differential diagnosis for head and neck pilomatricoma include sebaceous, dermoid and epidermoid cysts, metaplastic bone formation, foreign body reaction, parotid gland tumor, hematoma, osteochondroma, trichoepithelioma, and basal cell. When a malignancy is suspected, ultrasound examination, computed tomography (CT), or magnetic resonance imaging (MRI) scan combined with fine-needle aspiration can be helped to diagnosis. Treatment consists of surgical excision, and recurrent is rare after complete excision with clear margins.
We report a case of pilomatricoma with inflammation of the preauricular lesion in young boy.
| Case Report|| |
A 3-year-old boy consulted for a painless mass in the right cheek, which had been noticed 1 year previously. Clinical examination revealed a solitary, firm, well-circumscribed, freely mobile a 2 cm × 2 cm mass located in the right preauricular area, contrast-enhanced CT scan showed a well marginated, moderately well enhancing, ovoid soft tissue mass in the subcutaneous fat superficial to cheek area, and the mass partly attached to the overlying skin. There was a plump calcification in its center portion of the mass [Figure 1]. Fine-needle aspiration of the mass was cytologically consistent serous fluid with accompanying epithelial and inflammatory cells. The patient was taken to the operating room for an excision biopsy under general anesthesia. An elliptical incision was made around mass, which was excised along the margins. Histologically, the lesion was well circumscribed and composed of irregularly shaped masses of shadow or ghost cells and transitional cells. The pathologic features were compatible with a pilomatricoma.
|Figure 1: Contrast-enhanced computed tomography axial (a), coronal (b) and sagittal view (c) showed a well marginated, ovoid soft tissue mass (arrow) with intralesional calcification, partly attached to the overlying skin|
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| Discussion|| |
Pilomatricoma, also known as calcifying epithelioma of Malherbe, is benign skin neoplasm arising from sebaceous gland of the hair follicle outer root sheath. The tumor most commonly arise from the hair-bearing areas of the head and neck region, and followed by the upper extremities, the trunk and the lower extremity, in decreasing frequency. Especially the eyelid, preauricular area, and forehead are most frequent sites of the head.
Most of these tumors occur in children and young adult and slight female predominance., They are the second most commonly excised superficial masses in children, after epidermoid cysts. Pilomatricoma usually presents as an asymptomatic, solitary, firm or hard, freely mobile, dermal or subcutaneous nodule, and exhibits no fixation to neighboring tissues and has a cartilage-like hardness. Because pilomatricoma is hard to diagnose by its form, they can be misdiagnosed and as a consequence mistreated. The differential diagnosis of these lesions should include sebaceous, dermoid and epidermoid cysts, metaplastic bone formation, foreign body reaction, hematoma, osteochondroma, trichoepithelioma, and basal cell epithelioma. In addition, preuaricular or parotid area pilomatricoma is difficult to distinguish from tumor of the parotid, and it must be considered. Although radiologic imaging is of little diagnostic value for pilomatricoma, when a malignancy is suspected and evaluation of anatomical extension in a growing tumor is need, ultrasonography, CT, or MRI scan can be performed, combined with fine-needle aspiration. The characteristic CT findings are well-defined subcutaneous masses with various amounts of calcification.
Fine-needle aspiration cytology is not adequate as in our case and therefore not recommened for diagnosis. Excisional biopsy is the golden standard for diagnosis. Calcification is mostly seen in the ghost cell region with report incidence ranging from 69% to 85%.
| Conclusion|| |
Spontaneous regression of pilomatricoma is never observed, and malignant degeneration is extremely rare. Therefore, complete surgical excision including the overlying ulcerated skin is the treatment of choice. As most pilomatricoma arised in cosmetically sensitive areas and in young age, operator performing excisions need to adequately resection these lesions. Otolaryngologist should be familiar with pilomatricoma and consider it in the differential diagnosis of the calcified subcutaneous masses in preauricular region.
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Conflicts of interest
There are no conflicts of interest.
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